Since 5-hydroxy-1H-imidazole-4-carboxamide (henceforth also referred to as Compound A) or a salt thereof, or a hydrate thereof has a potent carcinostatic action, it is a medically useful compound as an anticancer agent (Patent document 1). In particular, it is an anticancer agent that exhibits a potent efficacy against solid carcinomas, against which chemotherapy has conventionally been considered difficult, and is also a highly safe anticancer agent that shows less side reactions, and thus it is a compound of which clinical applications are expected in a wide range of dosage forms such as oral agent, injection, ointment, and suppository. Tablets containing Compound A or a salt thereof, or a hydrate thereof are orally administered in a number of one to several tablets at one time.
It has been reported that the size of easily takable circular tablets is 7 to 8 mm in diameter, and the size of easily takable elliptical tablets is 9 mm in major axis (Non-patent document 1).
In general, tablets that can be easily handled and are suitable for taking should have appropriate hardness. In order to produce tablets having a required hardness by the direct tableting method, content of additives in tablets should be 60% or more, preferably 70% or more, of the mass of tablets (Non-patent document 2).
There is known a method for increasing base content in tablets by utilizing a binder and the wet granulation method (Non-patent document 3). Further, hardness of tablets can also be increased by using granules for making tablets granulated by a wet or dry granulation method to increase binding power of the granules at the time of tablet making.
Any tablet having a high content of Compound A or a salt thereof, or a hydrate thereof, an easily takable size, and superior dissolution property has not been known so far.